Circuit interrupter



Nov. 11, 1941. R, B |MMEL {g1-'AL 2,262,397

CIRCUIT INTERRUPTER Filed Jan. 24, 1940 ATTORN EY Patented Nov. 1l, 19412,262,397 CIRCUIT INTERRUPTER Ralph B. Immel and Ferdinand C. Iglehart,Wilkinsburg, Pa., assignors to Westinghouse Electric & ManufacturingCompany, East Pittsburgh, Pa., a corporation of Pennsylvania ApplicationJanuary 24, 1940, serial No. 315,370

13 Claims.

Our invention relates to circuit interrupters and more particularly tothermally-controlled, manually-operable snap-acting switches.

An object of our invention is t provide an inexpensive,ruggedly-constructed snap-acting switch which may function both as athermostat and a manually-operable switch.

A further object of our invention is to provide a manually orthermally-actuable switch which has a manual reset associated therewithfor preventing the thermal reengagement of the contacts afterdisengagementthereof.

Another object of our invention is to provide an improved thermally andmanually-operable snapacting switch which has a bimetallic member as themovable member thereof.

Still another object of our invention is to provide a thermally-actuablemanually-operable snap-acting switch in which the cooperating contactsthereof cannot be manually reengaged while the thermally-actuable memberremains in an open or hot position.

Other objects of our invention will either be pointed out specically inthe course of the following description of a device embodying ourinvention, or will be apparent from such description.

Referring to the accompanying drawing:

Figure 1 is a top plan view of a structure, embodying our presentinvention, with a portion of the casing removed;

Figs. 2, 3 and 4 are sectional views taken along the line II-II of Fig.l, illustrating the structure in its various operating positions;

Fig. 5 Ls a view taken along the line V--V of Fig. 6 illustrating amodified structure;

Figs. 6, 7 and 8 are views similar to Figs. 2, 3 and 4, respectively, ofthe modified structure illustrated in Fig. 5; and

Fig. 9 is a schematic wiring diagram illustrating the switch embodyingour invention associated with a load.

Referring to the accompanying drawing, in which like referencecharactersillustrate like parts in the several figures, we show athermallyactuable manually-operable snap-acting switch I0 comprising asupporting structure or casing I2, a. thermally-responsive switch memberI4, cooperating contacts including stationary contacts I6 and IGa andmovable contacts I8 and I8a attached to the member I4, an operatinghandle 20, a toggle connection 22 between the handle 28 and switchmember I4 for manually operating such member from one position toanother with a snap-action, and a heating element 24 which iselectrically associated with the cooperating contacts and thermallyassociated with the bimetallic member I4.

The supporting structure or casing I 2 is, in this instance, formed of asuitable insulating phenolic resin into substantially a hollow boxlikeshape. Ihe casing I2 includes an upper removable member 28 and a lowercup-shaped member 26 to receive the operating parts of the switchstructure I0. A centrally located protuberance 29 extends down from theupper member 28 to limit the upper movements of switch member I4. Avertically extending slot 30 is located or positioned Within one side ofthe lower member 26 of the casing I2 to receive the operating handle 20.A horizontally extending shallow slot 32 is positioned within the rearupwardly extending wall portion of the lower member 26 of casing I2 toreceive the bimetallic switch element I4 and to function as a fulcrumingpoint therefor. A plurality of outwardly extending cylindrical apertures34 are located within the side portions of the lower section 26 ofcasing I2 to receive suitable supporting members 38 of the handle 2|).While the preferred form of the casing I2 is herein described, it is tobe understood that any other suitable casing may be used in lieuthereof.

The thermally-responsive switch member I4 is, in this instance, abimetallic disc-type thermally-responsive element. However, it is to beunderstood that the switch member I4 need not be in the shape of a disc,but may, if desired, be, say, an elongated rectangularly-shapedbimetallic member. A plurality of movable contacts I8 and I8a arerigidly attached to the member I4 and, in this instance, areelectrically associated therewith. T'hese contacts are adapted tocooperatively engage suitable stationary contacts I 6 and I6a ashereinafter described. The switch member I4 fits into and is fulcrummedabout the slot 32 within the rear wall of member 26 of casing I2,

and when in an operative position is close to or may rest against acentrally located upwardly extending fulcruming post which is locatedcentrally with respect to the bimetal. `The bimetal is also attached tothe toggle connection 22 by means of an integral tongue I5 (see Fig. l),which is located at a point substantially diametrically opposite theengagement of switch member I4 with the casing I2. 'Ihe toggleconnection 22 is adapted to bodily move the disc-like switch member I4either upwardly or downwardly depending upon the position of theoperating handle 20, as hereinafterdescribed.

. switch member I4 is in a raised or inoperative position (see Fig. 4)the contacts I8 and I8a cannot become engaged with the stationarycontact I6 regardless of the curvature of such member.

However, the bimetallic switch member I4 may move from the operativeposition, as illustrated in Fig. 2, to an intermediate inoperativeposition (see Fig. 3). Such intermediate movement of the member I4 isnot controlled by the operating handle20 and toggle connection 22, ashereinabove described, but is controlled by the inherent thermal actionthereof, in a well-known m/anner. In other words, when the operatinghandle 2li is in'an upper position, the blmetallic switch member I4operates as a thermostat, from a lower operative position to anintermediate inoperative position, in response to the temperaturevariations thereof.

The stationary contacts I6 and Ia include, in this instance, upwardlyextending post-like members which pass .through the lower member 28 ofsupporting structure I2 and are rigidly attached thereto by suitablenuts I8. The contacts IB and I6a are positioned below the movablecontacts I8 and Ita, respectively, and are of such height as to makegoodcontact therewith as the switch moves to a closed or contact-engagingposition. ''he stationary contact I8 is also used as a terminal for theswitch structure I as hereinafter described.

The operating handle 28 is, in this instance, a tapered member which isadapted to extend into the casing I2 through the vertically slottedaperture 80. The handle 28 is hingedly attached to the lower member 28oi' casing I2\by means of a suitable substantially V-shaped elongatedhinging member 38. The hinging member 38 is rigidly attached to thehandle 28 and passes through the inner end of such handle so as to forman inwardly extending loop-portion 48 at the innermost end thereof. Theloop-portion 40 is adapted to cooperate with the toggle connection 22 asa supporting means. therefore, as hereinafter delscribed. The other orfree ends of the V-shaped hinge members 88 are bent substantiallyoutwardly and are positioned within the apertures 84 in member 26 toafford hinging means for the switch handle 20. It is, therefore, obviousthat the handley may move vertically within the slot 30, being limitedby the confines thereof, and rotate about the apertures 34, as fulcrums.

The toggle connection 22 between handle 20 and switch member I4comprises, in this instance, a substantially helically wound resilientmember. However, it is to be-understood that any other suitable toggleconnection between the operating handle '28 and the bimetallic disc I4may be used in lieu thereof. The helically wound resilienttoggle-connection 22 cooperates with the inner end oi handle 20 by beingpositioned aboutthe inwardly extending portion 48 of the hinge member 88at one end thereof so aslto rest against the inner end of the handle 20and cooperates with member I4 by iitting over the tongue portion I5 ofthe bimetallic member I4 at the other end thereof. The toggle connection22 is thus adapted to. convey the vertical movements of handle 28 to theswitch member I4 so as to pro- /duce a snap-action thereof, in awell-known manner, namely, by being compressed as the handle 20 is movedtoward the member I4 until it reaches its natural plane or a planeparallel to the member I4, at which time, with a continued movement ofthe handle 20, the toggle connection expands, causing the member I4 tomove upwardly with a snap-action. This action of the handle 20 andtoggle connection 22 moves the switch membei` I4 from one position toanother with a snap-action, regardless of the position of such handle.Further, the connection 22 is adapted to force the switch member I4downwardly when the handleis in an upper position and to force themember I4 upwardly when the handle is in a lower position, see Figs. 2and 4, respectively. It, therefore, follows that the handle 20 isadapted to bodily move the thermallyresponsive switch member I4 fromVone position to another with a snap-action through the cooperation of thtoggle connection 22.

The heating element 24 is, in this instance, rigidly attached at one endto the stationary contact .I6a and to a suitable terminal post'li at itsother end. The heater 24 is located substantially intermediate themember 26 of casing I2 and the under-surface of the thermally-responsiveswitch member I4. Such heater is thus in direct thermal` communicationwith the bimetal switch member I4 and is in series with the cooperatingcontacts IB and I8. 'I'he terminal post 3| is, in this instance, rigidlyattached to the casing I2 by means of. a. suitable nut 4I. 'Ihe post 3|,by meansvof nut 4I, functions not only as a support for the heater 24but as one 'of the terminals of the structure I0.

The switch structure I0 may be connectedin any desired circuit and isillustrated in Fig.. 9 as being in series withv a predetermined load 48.

With such an arrangement the stationary contact Ii is used as oneterminal and is connected tothe power supply by the lead line I1. Thecircuit then goes to movable contact I8, through member I4, and movablecontact I8a to stationary contact I8a, then to heater 24 to terminal II,line 21 to rload 48 and lead line 29 to the power supply. l

When operating the switch structure embodying our invention, in serieswith the suitable circuit, as illustrated in Fig. 9, and withthe switchin a closed or operated position (see Fig. 2) the cooperating contactsI8 and I8 are engaged, the operating handle 28 is in its upper position,and the heating element 24 is adapted to increase the temperature ofswitch member I4. The resilient toggle connection 22 also biases theswitch member I4 downwardly. With a continued e of current through'theswitch lstructure I8, the heating element 24 will cause thethermally-responsive switch member I4, in thermal communicationtherewith, to increase in temperature. Assuming the current passingthrough the circuit is above a predeterminedvalue, the switch member I4will increase in temperature to a predetermined value, at which timesuch member will ex upwardly with an inherent snap-action in awell-known manner. 'Ihe cooperating contacts I8 and I6 will then bedisengaged. disconnecting the load from the power supply. However, thehandle 20 will remain in an upper position (see Fig. 3). The heater 24and switch member I4 thus tend to cool. After cooling to a predeterminedclosing temperature value, the bimetallic member` I4 will, with thehandle in an operative position, then flex from the upwardly dishedposition (see Fig. 3) to a lower contact cooperating or engaged positionreconnecting the load to the power supply (see Fig. 2). In other words,the switch member I4 thus functions as a snap-acting thermostat inresponse to the heat produced by theheater 24 and the ambienttemperature associated therewith. During this time the operating handle28 has remained in its upper or operative position.

However, assuming that it is desired to manually disengage thecooperating contacts I 8 and I 6, the handle 20 is moved to a lowerposition. Toggle connection 2,2, after passing the neutral position,biases the thermally-responsive switch member I4 upwardly with asnap-action irrespective of its curvature. The cooperating contacts I8and I6 are then disengaged regardless of the temperature of the switchmember. The switch member I4 will then be in an upper or inoperativeposition regardless of its curvature see Fig. 4), it being understoodthat such member may flex from one curvature to another without causingthe cooperating contacts I8 and I8 to become engaged.

If it be desired to return the switch to its operative position, thehandle 20 is moved to its upper position, whereupon, assuming the switchmember I4 is curved into a cooperative position, the contacts I8 and I6will become reengaged with a snap-action. Thereafter, such switch againfunctions as a thermal switch.

It is, therefore, obvious that the switch structure shown as embodyingour invention comprises a thermally-responsive member or means adaptedto carry one of the cooperating contacts, and is capable of moving fromone position to another with a snap-acting movement in response to thetemperature variations thereof. Further, that the operating handleoperatively associated therewith, through a suitable toggle connection,is

adapted to operate such member in response to the manually-actuatedmovements thereof.

If it be desired, a manual resetting feature may be incorporated withthe switch structure embodying our invention, as hereinafter described.Such switch structure II,l as shown in Figs. 5, 6, 7 and 8, wouldcomprise the casing I2, operating handle 20, switch member I 4,cooperating contacts I6 and I8, and toggle connection 22. However,aresilient finger 42, which is rigidly attached at one end to the casingI2 and flexibly associated with the operating handle 20 at the otherend, would be associated therewith, it being understood that any othersuitable resilient member may be used in lieu thereof. The switchstructure II is identical with the switch structure I hereinabovedescribed, except that the elongated resilient finger 42 is operativelyassociated therewith.

The finger 42 is, in this instance, rigidly at-A tached to the upperportion of casing I2 by means of suitable rivets 44. The resilientfinger 42 is shaped or bent downwardly so as to engage the operatinghandle 20 and hold such handle in substantially its neutral plane, whenthe structure is in its normal operative position. With the handlemaintained in such a mid-position, it will be forced downwardly, throughthe cooperative action of toggle connection 22, into an inoperativeposition as the thermally-responsive switch member I4 iiexes from anengaging curvature (see Fig. 6) to a disengaged curvature (see Fig. 7).The member I4 thus moves into its upper or inoperative position as thehandle 28 moves downwardly. It, therefore, follows that with the memberI4 in such an upward position, the cooperating contacts I8 and I6 willnot become engaged, even though the member I4 returned to its normaloperating curvature (see Fig. 7). The bimetallic member I4 is then freeto flex to its original contact-engaging curvature, but cannot cause thecooperating contacts to be reengaged (see Fig. 8), as hereinabovedescribed.

If it be desired to reengage the cooperating contacts I8 and I 6 withthe member I4 flexed into an operative position (see Figg8), theoperating handle 20 must be moved Vupwardly to its uppermost position(see the dotted lines in Fig. 6). This action is similar to thathereinabove described and as illustrated in Fig. 2. However, the handle20 is moved into such a position against the biasing action of resilientfinger 42. The cooperating toggle connection 22 between handle 20 andmember I4 then forces the member I4 into a contact-engaging positionwith a snap-action, as previously described. However, upon releasing thehandle 20, the resilient member 42 moves such handle back tosubstantially its neutral or horizontal position.

If the bimetallic switch member I4 were not flexed into an operativeposition, but had an inoperative curvature (see Fig. 7), the switchcould not be reset. The operating handle 20 would, as the operatorreleased it from the upper or resetting position, illustrated by thedotted lines in Fig. 6, be first returned to the neutral or centralposition by resilient member 42, and then would be forced into its loweror inoperative position by toggle connection 22. The cooperatingcontacts I6 and I8 of our modified structure thus cannot be reengagedunless the bimetallic switch member I4 is rst flexed into anoperative'postion.

It is, therefore, obvious that, when the resilient member 42 isoperatively associated with the switch structure, such switch functionsas a manually or thermally-actuable switch which may be thermally ormanually disconnected, but which has a reset feature in that only theoperating handle can return the bimetallic switch member to itsoperative or engaging position.

It is further obvious that we have provided a circuit interrupter havinga movable thermallyresponsive switching member carrying the movablecontact and adapted to move with a snapacting movement in response totemperature variations, and having manually-operable means operativelyassociated therewith for manually actuating the movements thereof.

Various other modifications may be made in the structure embodying ourinvention without departing from the spirit and scope thereof, and wedesire, therefore, that only such limitations shall be placed thereon asare imposed by the prior art and the appended claims.

We claim as our invention:

1. A snap-acting switch comprising a supporting structure, aplurality ofcooperating contacts; movable thermally-responsive means for carryingone of said contacts, said means having a snapacting movement inresponse to temperature variations, an operating handle, and resilientmeans constituting the sole connection between the handle and thermalcontact carrying means for actuating the contact carrying means with asnap-action in response to the movements of the handle.

3. A snap-acting switch comprising a supporting structure, a pluralityof cooperating contacts, movable thermally-responsive means for carryingone of said contacts, said means having a snapacting movement inresponse to temperature variations, an operating handle, and resilientmeans directly connecting the handle and thermal contact carrying ,meansfor actuating the contact carrying means with a snap-action in response'to the movements of the handle, said movable thermal means beingsupported by the structure and the resilient means.

4. In a circuit maker and breaker, a supporting structure, a pluralityof contacts, a thermallyresponsive bimetallic movable switch member forcarrying one of said contacts adapted to vsnap from one position toanother in response to changes in the temperature thereof, an operatinghandle, and resilient means constituting the sole connection between thehandle and member for actuating the member with a snap-action in re- Vsponse to the movements otthe handle, said handle and resilient meansadapted to maintain the member in contact engaging location when in anoperating position and to maintain the member in a contact disengaginglocation when in an inoperative position.

5. A snap-acting switch comprising a supporting structure, a pluralityof cooperating contacts, a snap-acting bimetallic disc for carrying oneof said contacts, a helical spring, and manually-operable meansconnected through said spring to the disc for manually controlling themovements thereof in both directions.

6. A snap acting switch comprising a supporting structure, a pluralityof cooperating contacts, a snap-acting bimetallic member carrying one ofsaid contacts and operably mounted at one side in said structure. and ahandle resiliently connected to said bimetallic member at the oppositeside for controlling the operation thereof. Y

'7. A snap acting switch comprising a supporting structure, a pluralityof cooperating contacts,

ar snap-acting bimetallic member carrying oney of said contacts andoperably mounted at one side in said structure, an operating handle, anda helical spring having one end connected to the opposite side of saidbimetallic member and the other end connected to said handle.

8. A snap acting switch comprising a suppprting structure, a pluralityof cooperatinggcontacts, a snap-acting bimetallic member carrying' oneof said contacts and operably mounted at onel side in said structure,and a handle resiliently said handle extending in a plane approximatelyparallel to that of said bimetallic member.

9. A snap acting switch comprising a supporting structure, a pluralityof cooperating contacts, a snap-acting bimetallic member carrying one ofsaid contacts and operably mounted at one side in said structure, anoperating handle, means for mounting said handle in said structure formovement in a plane substantially perpendicular to the plane of saidbimetallic member, and resilient means for interconnecting said handleand said bimetallic member.

10. A snap acting switch comprising a supporting structure, a pluralityof cooperating contacts, a snap-acting bimetallic member carrying one ofsaid contacts and operably mounted at one side in said structure, anoperating handle, wire means attached to said handle and having outerends pivotally mountedv in said structure along an axis transverse tothe direction of movement of said bimetallic member when heated, andspring means for directly connecting said handle and said bimetallicmember.

11. A snap acting'switch comprising a sup- Aporting structure, aplurality of cooperating conand an abutment for assisting in theoperation s of said bimetallic member mounted in said structureintermediate said handle and said one side of said bimetallic member.

12. A snap acting switch comprising a supporting structure, a pluralityof cooperating contacts, a snap-acting bimetallic member carrying one ofsaid contacts and operably mounted at one side in said structure, ahandle resiliently connected to said bimetallic member at the oppositeside for controlling the operation thereof in both directions, and aspring member secured to said structure for preventing movement of saidhandle to one of its extreme positions by operation of said bimetallicmember in response to temperature.

13. A snap acting switch comprising a supporting structure, a pluralityof cooperating contacts, a snap-acting bimetallic member carrying one ofsaid contacts and operably mounted at one side in said structure, alhandle resiliently

